1. Field of the Invention
This disclosure relates to a thin film transistor substrate, a display device having the thin film transistor substrate, and a method of manufacturing the display device.
2. Description of the Related Art
A thin film transistor is a three-terminal element having a gate terminal, a source terminal, and a drain terminal. It is an active element in which a semiconductor layer deposited on a substrate is used as a channel layer for transport of electrons or holes, where a voltage can be applied to the gate terminal to control a current flowing in the channel layer, thus acting as a switch to control the current between the source terminal and the drain terminal. Commercially, the most widely used thin film transistors are metal-insulator-semiconductor field effect transistors in which the channel layer is composed of a polycrystalline silicon layer or an amorphous silicon layer.
As the semiconductor layer, a metal oxide may also be used. During the formation of the metal oxide, oxygen defects in the metal oxide may form, which can make the metal oxide unsuitable for use as a channel layer. Accordingly, it is therefore desirable to form a metal oxide without oxygen defects that is suitable for use as a channel layer in a thin film transistor.